Eyeglass lens and method of making same



Nov. 20, 11934. N. M. STANLEY EYEGLAS-S LENS ANDl METHOD OF MAKING SAME Filed June 8, 1952 2 Sheets-Sheet 1 Wmwwm INVENTOR NATHAN M. 6TH/VLEX AVITORNEY Nov. 20, 1934. N. M. STANLEY 1,981,815

` EYEGLASS LENS AND METHOD OF MAKING SAME Filed June 8, 1952 2 Sheets-Sheet 2 www 4 `9 INVENTOR NATHAN M. STANLEY.

BYZ Ari ATTORNEY Patented Nov. 2.0, 1934 VEYEGLASS-LENS AND METHoD or MAKING Nathan M- y Stanleyf.Dayton,;.9hio' l Application June 8,1932, serialnobslao'zs 5 Claims.

It is the .object ofmy invention to provide ,a three-piece bifocal lens. I. Y

Itis Amy object to provide an accuratelyformed insert of one index ofrefraction supported by and embraced on all sides except its faceby adistance lensvof another index of refraction without Waste iofmaterial and .at the same time Without the necessity of eccentric countersinking and of multiple piece inserts, thereby yeliminating the fusing operation necessary for the manufacture of .an inserty of multiple indices-of refraction.

Referring., to l the drawings, Figure .1 is a circular piece of glass of one index of refraction for distance vision.

Figure 2 shows the face thereof having a concentrically ground circular countersink. 1

Figure 3 is a plan view of the distance'lensin Figure 2 with a circular button or insert fused therein. y

Figure 4 shows the completed article in Figure 3 severed in half.

Figure 5 shows al second circularpiece of distance glass severed rin, half to form` the upper halves of the completed lens.

Figure 6 shows these completedr together preliminary to fusing.

Figure 'Tshows the completedlens fused. v

Figure 8 is a section on the line 8-8 .through the completed-fused lens.

Figure 9 is a section on the line 9-9of Figure 2.

Figure 10 is a section .on the line.10-10'of Figure 3.

Figure 11 is an end elevation of one Iof the halves shown in Figure 4 after it has beenrough ground to impart toit a grey surface.'

Figure 12 is a vertical section through .the plaster of paris holder for thehalves of the lens shown in Figure 4 when they are ground.

Figure 13is a-section on the line 13-13 of .Figure 5.

Figure .14 is aplan view of the lens halves after the countersunk portions have been ground therein.

Figure 15 is a section on the line 15-15 of Figure 14, showing the block of lens halves superposed upon a surfacing tool.

Figure 16 is a front elevation of the modified form of the countersunk half of the lens.

Figure 17 is a section on the line 17--17 of Figure 16.

Figure 18 is a front elevation of the countersunk portion of the lens with the insert in position.

Figure 19 is a section on the line 19-19 of Figure 18.

halves -joined `lligure 2,0'shows avblank severed onan arcuate line.

Figure .2,1y shows the ftwoA halves of the .lens abutting one another.

Figure f2 2 shows a complete fusedjlens.

jv-FigureZS is asection ontheline 23--23 of Figure 22.

-Figure 2.4-is-an end elevation of Figure 1 8` showing theeclges of the insertandofthe countersunk half of `themainilens suitably greyed Referring. to thedrawings in. detail, lisa circular-piece ofrgassof an .index of refraction suitableifor distance vision. AcOuntersink 2 having a ,spherical surface y.and `circular outline is ground therein. In tliiscountersink is fusedin the-,usualgmannerya,button 3 having `a back 4 with a .spherical Surface.. Thisv .completed farticleisfthen-fsevered along the line5 in two semicirculargparts. These parts are embedded fin plaster ;of;paris sdthattheir edges 5 maybe ground toriimpart afgrey lfinish 'l as indicated in`=vFigure- 11. If fitis desired to remove the grey surface the edgescan-be polished. These halves withftheinsertare thenremoved from the plaster of ,Haris .where they are lresting upon the support 77. -VThey-,arefused edge to edge to the semicirculaphalves; 8 along the edge59 thereof, `which halves formathe upper portion. of the completed lens. fIhe position Yof ,the parts will be seen in Figure A6. The upper halves -8 are formedby splitting thefvplate 1 in two parts.

JTheze,Orrualeted lens appears asin Figure 7. Ihe';.upp er and ;lower;halvesbeingof the same index of refraction and of the same typeoffglass, which Scrown glass fused together, eithershow no junction line or one thatis not objectionable dueto the'grey surface 4'7. The insert. of a differlent index, of refraction marked 3 is located the vproper position inthe distance lens. `IBy suitable edging and grinding it maybe located eccentricallyof thecenter of the major lens in the usual manner. Y'Itis shown'in the' blankform in Figures 7 and 8.

It will be understood that the surface of Figure 3 is usually ground so that the surface Will appear as in Figure 11 rather than as in Figure 10.

The steps of the process comprise the provision of a circular piece of glass 1, the grinding of a countersink 2 in the face thereof, preferably concentrically of the glass 1, fusing a button of a different index of refraction in the face, grinding the face, splitting the completed article in half, treating the edges so split; and then splitting a plain piece of glass 1 in half and either treating. or not the edges as may be desired;

and then fusing the plain half to a half carrying a fused insert in the manner described.

Referring to Figures 14 to 24 inclusive, 10 indicates a supporting bowl in which the major lens halves 1 are imbedded in pitch 11. This bowl is inverted and the grinding member l2 grinds the countersunk portions 13 therein. Thus a circular grinding member having a spherical face is adapted to grind semi-spherical countersunk portions out of the lens halves l. These halves are preferably arcuate on the at face 14 so that the eye in travelling laterally above the top of the insert 3 will not be interfered with by any remaining line showing the juncture between the upper and lower halves of the major lens when the upper and lower halves are fused to one another. It is therefore feasible to grey the top of the segment by either grinding or etching. If only the top of the segment is given a grey surface, the juncture line between the major portion of the lens being below the general lateral line of vision, such juncture line will not interfere with the vision of the wearer.

If desired, the entire surface of the abutting edge of the lower half of the major lens as well as the top of the segment may be ground to give it a grey surface.

When etching is employed, the lens is embedded in a mixture of beeswax, tallow, oolophony and powdered asphalt kneaded together. The entire lens is surrounded except the portion to be etched, or the portion to be etched is surrounded with a rim of the foregoing material to prevent the etching material from spreading over the parts not to be etched.

The etching iluid may be of any desired character, such as commercial hydrouorio acid in the proportion of 240 cc., 600 grams of powdered crystallized soda and 100 cc. of water. After etching the etched surface can be washed with water. Thereafter the surface is treated with an opaque etching fluid or paste in order to secure a greater degree of opacity or greyness. Such greyed surfaces are shown in Figure 24.

` If desired, the upper surface of the combined segment and major portion of the lens may have a curvature such as shown in Figures 16, 18, 20, 21 and 22, and with such a curvature, the line of juncture of the major portion of the lens being below generally the top of the segment, will not interfere with the vision of the wearer, as heretofore described. To grind the halves to this curvature they may be held as indicated in Figure l2.

My preferred form of invention is that shown in Figure 14 for forming the countersink where the countersink is only formed in one half of the lens, thereby forming a.semi-circular countersink in which is mounted a semi-circular button. The two are fused together and then a substantially semi-circular major lens portion constituting the top half of the lens is fused to the lower half and to its button or insert segment.

By this manner of construction, the lens of my invention is adapted to easy and economical manufacture. By constructing the lens halves and button halves at the outset, the dimculty of afterward splitting a whole blank after fusing is avoided: in practice it is quite difficult to split any blank, such as that shown in Figure 4, exactly through the center, and the halves usually come out unequal in size. Furthermore, the cut is loften uneven, so that the edges must be ground off for several millimeters before the ridges or chipped portions are removed. By constructing the halves separately, each half may be made slightly larger than necessary, and always edged down to exactly the same size. In addition to these advantages, there is no necessity of having to split the blank containing the heavy button, as shown in cross section in Figure l0, an operation which would create a very irregular result.

It will be understood that I desire to comprehend within my invention such modifications as may be necessary to adapt it to varying conditions and uses.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

l. In a method of manufacturing eyeglass lenses, grinding a semi-circular countersink in a semi-circular distance lens, and inserting and fusing a semi-circular button therein.

2. In a method of manufacturing eyeglass lenses, grinding a partially circular countersink in a partially circular distance lens, inserting a partially-circular button therein and fusing, and surfacing an arcuate face on the end of the button and the end of the distance lens.

3. In a method of manufacturing a bifocal eyeglass lens, grinding a semi-circular countersink in a semi-circular distance lens, fusing a semicircular button insert into said countersink in the distance lens and fusing as an upper half a semicircular distance lens to the edge of the lower half of the distance lens and the edge of the button insert. f

4. In a method of manufacturing an eyeglass lens, forming a countersink of non-circular outline extending to the edge of a piece of glass,

securing a non-circular button therein, and uniting the blank thus formed edge-to-edge with another piece of glass.

5. In a method of manufacturing an eyeglass lens, forming a countersink adjacent the edge of a piece of glass, securing a button of partially 1 circular outline therein, surfacing the edge having the button to an even curvature, and uniting the blank thus formed edge-to-edge with another piece of glass having a corresponding edge cur- Vature.

NATI-IAN M. STANLEY. 

